init basic

ccompiler/frontend/parser/ast/decl.c

@@ -0,0 +1,94 @@
+#include "../parser.h"
+#include "ast.h"
+#include "../symtab/symtab.h"
+
+/**
+ * 0 false
+ * 1 true
+ */
+int peek_decl(struct Parser* parser) {
+    flushpeektok(parser);
+    switch (peektoktype(parser)) {
+        case TOKEN_STATIC:
+        case TOKEN_EXTERN:
+        case TOKEN_REGISTER:
+        case TOKEN_TYPEDEF:
+            error("not impliment");
+            break;
+        default:
+            flushpeektok(parser);
+    }
+
+    switch (peektoktype(parser)) {
+        case TOKEN_VOID:
+        case TOKEN_CHAR:
+        case TOKEN_SHORT:
+        case TOKEN_INT:
+        case TOKEN_LONG:
+        case TOKEN_FLOAT:
+        case TOKEN_DOUBLE:
+            return 1;
+        default:
+            flushpeektok(parser);
+    }
+}
+
+struct ASTNode* parse_decl_val(struct Parser* parser) {
+    flushpeektok(parser);
+    // parse_type
+    enum TokenType ttype;
+    struct ASTNode* node;
+
+    struct ASTNode* type_node = parse_type(parser);
+    struct ASTNode* name_node = parser_ident_without_pop(parser);
+    
+    node = new_ast_node();
+    node->decl_val.type = type_node;
+    node->decl_val.name = name_node;
+    node->type = NT_DECL_VAR;
+    symtab_add_symbol(parser->symtab, name_node->syms.tok.constant.str, node);
+    
+    ttype = peektoktype(parser);
+    if (ttype == TOKEN_ASSIGN) {
+        node->decl_val.expr_stmt = parse_stmt(parser);
+        if (node->decl_val.expr_stmt->type != NT_STMT_EXPR) {
+            error("parser_decl_val want stmt_expr");
+        }
+    } else if (ttype == TOKEN_SEMICOLON) {
+        poptok(parser);
+        expecttok(parser, TOKEN_SEMICOLON);
+    } else {
+        error("parser_decl_val syntax error");
+    }
+    return node;
+}
+
+// 类型解析入口改进
+struct ASTNode* parse_decl(struct Parser* parser) {
+    flushpeektok(parser);
+    int idx;
+    enum TokenType ttype;
+    struct ASTNode* node;
+    
+    if (peek_decl(parser) == 0) {
+        error("syntax error expect decl_val TYPE");
+    }
+    if (peektoktype(parser) != TOKEN_IDENT) {
+        error("syntax error expect decl_val IDENT");
+    }
+
+    ttype = peektoktype(parser);
+    switch (ttype) {
+        case TOKEN_L_PAREN: // (
+            node = parse_func(parser);
+            break;
+        case TOKEN_ASSIGN:
+        case TOKEN_SEMICOLON:
+            node = parse_decl_val(parser);
+            break;
+        default:
+            error("syntax error expect decl_val ASSIGN or SEMICOLON");
+            return NULL;
+    }
+    return node;
+}